The double-lined arrow in the diagram is an alternative notation that shows a unit being hosted on another unit.

图表中的双行箭头是一种提示：寄主于另一个单元上的单元。

youdao

The double-lined arrow in the diagram is an alternative notation that shows a unit being hosted on another unit.

图表中的双行箭头是一种提示：寄主于另一个单元上的单元。

youdao